NO. 10 HUMAX HAIR AND PRIMATE PATTERNING MILLER 5 



Though a bare or nearly bare condition of the mouth area is the 

 usual condition among nonhuman primates, it is not universal. Beards 

 like those of the male Caucasian or Australian occur in the orang 

 (pi. 2, fig. 6), in the bearded African guenon shown at the top of 

 Plate I, and in a South American monkey {Pithecia chiropotes) of 

 which I have not been able to obtain a photograph. Moustaches are 

 not common among primates. Even that of the fuU-beardcd orang 

 is poorly developed. But the South American Mysiax hnpemtor 

 (pi. 2, fig. 7) goes far to make up for this deficiency. While neither 

 moustache nor beard is peculiar to man the strong development of 

 both together appears to be a human specialty. 



Nothing exactly like the human eyebrows is known in other pri- 

 mates, but the brow region is one where patterns are made in great 

 profusion. Sometimes these brow patterns take the form of light 

 or dark stripes (as shown in pi. i and in pi. 4, figs. 10 and 13) ; some- 

 times they are made by lines of hair differing in quality and direction 

 from that of the head (pi. 2, fig. 8), thus showing a near approach 

 to the condition found in man. Human eyebrow hair, as is well known, 

 often differs in color from the hair of the crown. In such cases 

 (pi. 4, figs. II, 12) it is usually darker than the crown hair, after 

 the manner of the gray-cheeked mangabey (pi. 2, fig. 8) or the 

 Himalayan langur (pi. 4, fig. 10) ; rarely if ever is it conspicuously 

 lighter, after that of the white-browed gibbon (pi. 4, fig. 13). 



This normal human pattern does not always remain constant 

 throughout life. Changes of two kinds usually take place; and the 

 courses of both kinds tend to follow lines that can be traced through 

 the group of primates at large. 



TURNING BALD 



With arrival at full maturity a considerable percentage of human 

 males undergo a modification of their hair pattern that serves to 

 differentiate them still further from the females. The forehead line 

 begins to rise, either uniformly along its entire extent (pi. 3, fig. i), 

 or, more commonly, by pushing back a blunt reentrant wedge on each 

 side (pi. 3, fig. 4). Frequently a bare spot begins to form at the 

 same time on the top of the crown (pi. 3, fig. 6), and the hair of the 

 entire median part of the crown becomes sparse. These changes may 

 continue until the bald forehead area has been carried back over the 

 dome of the head, leaving a well-haired border extending around the 

 sides and across the nape (pi. 3, fig. 8). 



This series of maturity changes in the hair covering of the human 

 male head has been the subject of endless speculation. By a few 



